CN102333908A

CN102333908A - Metal-coated polyimide resin substrate with excellent thermal aging resistance properties

Info

Publication number: CN102333908A
Application number: CN2010800091373A
Authority: CN
Inventors: 吉田拓
Original assignee: JX Nippon Mining and Metals Corp
Current assignee: JX Nippon Mining and Metals Corp
Priority date: 2009-02-25
Filing date: 2010-02-17
Publication date: 2012-01-25
Anticipated expiration: 2030-02-17
Also published as: CN102333908B; WO2010098235A1; KR20110110342A; KR101327618B1; SG173595A1; JPWO2010098235A1; EP2402485A1; US20110318602A1; EP2402485A4

Abstract

Provided is a metal-coated polyimide resin substrate that exhibits a high level of adhesion after aging at 150 DEG C for 168 hours without a reduction in the initial close adhesion between a metal-coated polyimide resin film and a metal layer. The metal-coated polyimide resin substrate is produced as follows. After surface modification is applied to one surface or both surfaces of a polyimide resin film using a wet method, a dry method, or a combination thereof, a barrier layer is formed using a wet method, a seed layer is subsequently formed using a wet method or a dry method, and a conductive film is formed on the surface layer using a wet method. The metal-coated polyimide resin substrate is characterized in that the thickness of a mixed layer of a polyamide residue and a barrier-metal layer residue at the peeled surface on the conductive film layer side of said metal-coated polyimide resin substrate after the metal-coated polyimide resin substrate is subjected to a 90 DEG peel test is 2.6 nm or less, in terms of Si sputtering speed, when measured by means of a depth profile analysis using a time-of-flight secondary ion mass spectrometer (TOF-SIMS), and the peel strength retention rate after a 168-hour aging test at 150 DEG C (peel strength after aging at 150 DEG C for 168 hours/initial peel strength) is 50% or higher.

Description

The metal-coated polyimide resin substrate that has excellent thermal aging resistance property

Technical field

The present invention relates to can be used as the non-adhesive flexible laminated material that the installing material of electronic units such as flexible printed board, TAB, COF uses, the method for manufacture of the metal-coated polyimide resin substrate that particularly has excellent thermal aging resistance property.

Background technology

In the Kapton laminated FCCL (flexible copper-clad foil laminate) of the metal conductor layer that is made up of copper is arranged mainly, be widely used as the material of the circuit card in the electronic industry.Wherein, the non-adhesive flexible layer pressing plate (particularly double-deck flexible duplexer) that does not have an adhesive layer at Kapton and metal interlevel causes concern along with the thin spaceization of wiring width.

The flexible laminated body of non-adhesive, the particularly method of manufacture of the non-adhesive flexible laminated body corresponding with thin space; Following method is arranged: on polyimide resin film, be pre-formed blocking layer and Seed Layer through dried plating methods such as sputter, CVD, vapor depositions, then through plating method form as the metal level of conductor layer, so-called metallization (メタライジ Application グ method).

In this metallization; In order to improve the closing force of metal level and Kapton; Before forming metal level, carrying out to improve with the adaptation of barrier metal through plasma treatment to the polyimide resin film surface is the surface-treated (referenced patent document 1 and patent documentation 2) of purpose.

In addition, also proposed on polyimide resin film, to form blocking layer and Seed Layer in advance, formed scheme through plating method then as the metal level of conductor layer through electroless plating method.

In the method; Before forming metal level; Polyimide resin film impregnated in the solution that is made up of alkali metal hydroxide, and carrying out with raising is the surface-treated (referenced patent document 3) of purpose as the absorption of the catalyzer of follow-up electroless plating motivating force and the adaptation of raising and barrier metal.

The surface modification treatment of said polyimide resin film has big influence to the adaptation of polyimide resin film and metal level, on making, is the treatment process of particularly important.

As the desired mechanical characteristics of the flexible laminated body of non-adhesive, the stripping strength at initial stage has importance with long-term through stripping strength later, in recent years as high reliability request, particularly becomes important through stripping strength later for a long time.

In addition, as the evaluation method of long-term warp stripping strength later, generally be to estimate through measuring as peeling off behind the heat-proof aging (150 ℃, 168 hours) of activated deterioration test.

Recently; Propose to utilize silver nitrate aqueous solution that the polyimide resin film of handling through modification is dyeed the back with transmission type microscope (TEM) observation section, confirmed the method (referenced patent document 4) of the stripping strength behind initial stage and the heat-proof aging according to the thickness of its modified layer.

But; In the surface-treated of the polyimide resin film of reality; Can produce the material with the various molecular structures that include the functional group that helps adaptation according to treatment condition, therefore, aforesaid method is only only estimated the surface reforming layer through cma staining with specific material; Even the modified layer thickness in the above-mentioned evaluation is same, also produce the problem of difference between the peeling strength test result of existence and reality.

The prior art document

Patent documentation

Patent documentation 1: No. 3173511 communique of Japanese Patent

Patent documentation 2: Japan special table 2003-519901 communique

Patent documentation 3: TOHKEMY 2005-154895 communique

Patent documentation 4: TOHKEMY 2007-318177 communique

Summary of the invention

The high metal-coated polyimide resin substrate of closing force after the situation that the purpose of the application invention is to be provided at the initial stage closing force that does not reduce metal-coated polyimide resin film and metal level wore out in following 150 ℃, 168 hours.

In view of above-mentioned problem, the present invention provides following invention:

1) a kind of metal-coated polyimide resin substrate; It is for after carrying out surface-treated through wet method or dry method or their combination on the single face of polyimide resin film or the two sides; Form the blocking layer through wet method, form Seed Layer through wet method or dry method afterwards, and form the metal-coated polyimide resin substrate that conductive cell envelope obtains through wet method on its top layer; It is characterized in that

On the release surface of this metal-coated polyimide resin substrate being carried out 90 ° of conductive cell envelope layer sides after the stripping test; Use time of flight secondary ion massspectrometry analytical equipment (TOF-SIMS) to carry out the polyimide residue that the depth direction analysis obtains and be scaled below the 2.60nm with the Si sputtering rate with the mixolimnion thickness of barrier metal layer residue, the stripping strength conservation rate (150 ℃, 168 hours aging stripping strength/initial stage stripping strengths afterwards) after 150 ℃, 168 hours weathering tests is more than 50%.

In addition, the application's invention provides following invention:

2) as above-mentioned 1) described metal-coated polyimide resin substrate, it is characterized in that said Seed Layer and conductive cell envelope are copper, said blocking layer is nickel or their alloy.

3) as above-mentioned 1) or 2) described metal-coated polyimide resin substrate, it is characterized in that,

Surface-treated on the said polyimide resin film is carried out with the combination that strong acid solution floods through plasma body, UV, alkali hydroxide soln dipping or they.

The invention effect

The metal-coated polyimide resin substrate of the application's invention; Particularly under the situation of the initial stage closing force after not reducing Kapton and metal interlevel range upon range of; Can improve the closing force after wearing out, thereby have excellent results aspect the formation fine pattern.

Description of drawings

Fig. 1 is on the release surface of expression metal level side, and the depth direction analysis through using time of flight secondary ion massspectrometry analytical equipment (TOF-SIMS) is carried out the figure that inquiry agency gets result's summary to the mixolimnion thickness of polyimide residue and barrier metal (Ni) layer residue.

Fig. 2 is the figure of relation of thickness and the stripping strength conservation rate of expression polyimide mixolimnion.

Embodiment

Generally speaking; After carrying out surface-treated through wet method or dry method on the single face of polyimide resin film or the two sides; Form the blocking layer; On this blocking layer, form Seed Layer, and on this Seed Layer, form certain thickness conductive cell envelope, make metal-coated polyimide resin substrate thus.

That makes like this does not have the flexible laminated body of non-adhesive (particularly two sheets of flexible duplexer) of adhesive layer at Kapton and metal interlevel; As FCCL (flexible copper clad foil layered product); Material as the circuit card in the electronic industry is widely used; But,, require to improve the closing force of metal level and Kapton along with the thin spaceization of nearest wiring width.

As its evaluation method, generally speaking, through measuring normality stripping strength (initial stage stripping strength) and carrying out as the stripping strength behind the heat-proof aging (150 ℃, 168 hours are aging) of activated deterioration test.

As stated, as high reliability request, particularly long-term warp stripping strength later becomes important, therefore requires to improve 150 ℃, the 168 hours stripping strength conservation rates (heat-resisting stripping strength/normality stripping strength) after the weathering test as far as possible.

In order to improve such stripping strength conservation rate; Knownly preferably surface modification treatment is carried out on the surface of polyimide resin film through wet method or dry method; But this surface modification treatment increases stripping strength through which kind of mechanism or phenomenon and does not make much of as yet, in addition; The modification processing is also implemented through trial and error itself, therefore has the problem that is difficult to keep the constant modification levels.

Therefore, the application contriver has carried out probe to 90 ° of structures of peeling off the depth direction of middle metal level side release surface of metal-coated polyimide resin substrate.The result finds, has the mixolimnion of the blocking layer (nickel, its alloy layer) that forms after the surface modification treatment and polyimide.

Though also depend on the modification processing method of polyimide resin,, generally speaking, modification is handled when excessive, and barrier metal is sneaked into increase in polyimide modified layer, thus the mixolimnion of barrier metal and polyimide thickens.

And find the descend thickness of mixolimnion of polyimide and barrier metal of metal level side on the release surface that the initial stage of resulting from peels off of the stripping strength behind the heat-proof aging.

Find that promptly the mixolimnion of polyimide and barrier metal is thick more, the copper that then has the catalyst oxidation effect is diffused in the polyimide layer through this mixolimnion more easily, thereby the stripping strength in the heat-proof aging descends.

Therefore can find out; Through regulating the polyimide of peeling off middle metal level side release surface at initial stage and the thickness of metal mixed layer; Can keep the stripping strength behind the higher heat-proof aging, and can be by the stripping strength behind the thickness prediction heat-proof aging of the polyimide of the metal level side release surface at initial stage and metal mixed layer.

Be illustrated among Fig. 1 on the release surface of metal level side, the depth direction analysis through using time of flight secondary ion massspectrometry analytical equipment (TOF-SIMS) is carried out the summary that inquiry agency gets the result to the mixolimnion thickness of polyimide residue and barrier metal (Ni) layer residue.

As shown in Figure 1, polyimide residue (C-C) converts with sputter Si and near degree of depth 2nm, forms the peak, and on the other hand, barrier metal (Ni) converts with sputter Si and near degree of depth 4.5nm, forms the peak.It wherein the mixolimnion of polyimide and metal.

By after embodiment and the comparative example stated can find out that obviously this mixolimnion is the reason that causes the stripping strength conservation rate to descend.

According to above content; The application contriver is through discover in a large number; The Si sputtering rate that obtains with the depth direction analysis through TOF-SIMS when the mixolimnion thickness of polyimide and barrier metal layer on the metal level side release surface is scaled 2.60nm when following, can increase by 150 ℃, the 168 hours stripping strength conservation rates (heat-resisting stripping strength/normality stripping strength) after the weathering test.And, at this moment, can realize that the stripping strength conservation rate is more than 50%.

Embodiment

Below, describe based on embodiment and comparative example.It should be noted that present embodiment only is an example, the invention is not restricted to this example.That is, the present invention also comprises alternate manner or distortion.

(embodiment 1)

As polyimide resin film, use the カプト Application 150EN of E.I.Du Pont Company.As surface-modification method, this polyimide resin film is impregnated in the potassium hydroxide aqueous solution, and washs with pure water.Then, apply operation, be impregnated into and the silane coupling agent that contains the functional group with metal capturing ability is mixed with precious metal chemical complex or react and in the solution that obtains, and wash with pure water as catalyzer.

After this was handled, as the electroless plating operation, using no electrolytic nickel-boron was plating bath, forms the nickel dam of 0.15 μ m, after the pure water washing, carried out 150 ℃ thermal treatment, and the nickel dam that forms 0.05 μ m forms the nickel dam of 0.20 μ m altogether then with the pure water washing.Then, in the electrolytic copper free plating bath, on nickel dam, form the electrolytic copper free Seed Layer, then through electroplating the copper conductor layer that forms 8 μ m.

Metal-coated polyimide resin substrate to such formation; Carry out 90 ° of stripping strengths and measure, and the thickness of the mixolimnion of the polyimide of the depth direction assay determination metal layer side release surface of use time of flight secondary ion massspectrometry analytical equipment (TOF-SIMS) and barrier metal.

The result of said determination is as shown in table 1.

Table 1

As shown in table 1, the normality stripping strength is 0.55kN/m, and heat-resisting stripping strength is 0.45kN/m, and stripping strength conservation rate (heat-resisting stripping strength/normality stripping strength) is 82%.And be 0.51nm through the Ni of TOF-SIMS mensuration and the mixolimnion of polyimide this moment.

The thickness of this Ni and polyimide mixolimnion is little, satisfies the condition of the application's invention, the result, and the stripping strength conservation rate is 82%, demonstrates good characteristic.

(embodiment 2)

As polyimide resin film, use the カプト Application 150EN of E.I.Du Pont Company.As surface-modification method, this polyimide resin film is carried out being impregnated in the sulfuric acid after the UV irradiation, wash with pure water then.Then, apply operation, be impregnated into and the silane coupling agent that contains the functional group with metal capturing ability is mixed with precious metal chemical complex or react and in the solution that obtains, and wash with pure water as catalyzer.

After this was handled, as the electroless plating operation, using no electrolytic nickel-boron was plating bath, forms the nickel dam of 0.2 μ m, and washs with pure water.Then, in the electrolytic copper free plating bath, on nickel dam, form the electrolytic copper free Seed Layer, then through electroplating the copper conductor layer that forms 8 μ m.

The result of said determination is as shown in table 1.

As shown in table 1, the normality stripping strength is 0.61kN/m, and heat-resisting stripping strength is 0.55kN/m, and stripping strength conservation rate (heat-resisting stripping strength/normality stripping strength) is 90%.And be 0.13nm through the Ni of TOF-SIMS mensuration and the mixolimnion of polyimide this moment.

The thickness of this Ni and polyimide mixolimnion satisfies the condition of the application's invention, the result, and the stripping strength conservation rate is 90%, demonstrates very good characteristic.

(embodiment 3)

As polyimide resin film, use the カプト Application 150EN of E.I.Du Pont Company.As surface-modification method, this polyimide resin film is carried out being impregnated in the nitric acid after the UV irradiation, wash with pure water then.Then, apply operation, be impregnated into and the silane coupling agent that contains the functional group with metal capturing ability is mixed with precious metal chemical complex or react and in the solution that obtains, and wash with pure water as catalyzer.

The result of said determination is as shown in table 1.

As shown in table 1, the normality stripping strength is 0.56kN/m, and heat-resisting stripping strength was 0.39kN/m in 150 ℃, 168 hours, and stripping strength conservation rate (heat-resisting stripping strength/normality stripping strength) is 70%.And be 1.60nm through the Ni of TOF-SIMS mensuration and the mixolimnion of polyimide this moment.

The thickness of this Ni and polyimide mixolimnion is minimum, satisfies the condition of the application's invention, the result, and the stripping strength conservation rate is 70%, demonstrates good characteristic.

(comparative example 1)

As polyimide resin film, use the カプト Application 150EN of E.I.Du Pont Company.As surface-modification method, this polyimide resin film is impregnated in the potassium hydroxide aqueous solution, wash with pure water then.Then, apply operation, be impregnated into and the silane coupling agent that contains the functional group with metal capturing ability is mixed with precious metal chemical complex or react and in the solution that obtains, and wash with pure water as catalyzer.

The result of said determination is as shown in table 1.

As shown in table 1, the normality stripping strength is 0.63kN/m, and heat-resisting stripping strength is 0.28kN/m, and stripping strength conservation rate (heat-resisting stripping strength/normality stripping strength) is 44%.And be 2.87nm through the Ni of TOF-SIMS mensuration and the mixolimnion of polyimide this moment.

The thickness of this Ni and polyimide mixolimnion is big, the condition of discontented unabridged version application invention, and also the stripping strength conservation rate is 44%, variation.

The thickness of above embodiment and the blocking layer of comparative example and polyimide mixolimnion and the relation of stripping strength conservation rate are as shown in Figure 2.

Obviously can find out from this Fig. 2; Along with the thickness increase of the Ni that measures through TOF-SIMS with the mixolimnion of polyimide; Have the tendency that stripping strength conservation rate (heat-resisting stripping strength/normality stripping strength) descends, can confirm: it is to be necessary more than 50% that the mixolimnion thickness of polyimide residue and barrier metal layer residue is scaled below the 2.60nm for making the stripping strength conservation rate with the Si sputtering rate.

Industrial applicability

The application's invention provides a kind of metal-coated polyimide resin substrate; It is after carrying out surface-treated through wet method or dry method or their combination on the single face of polyimide resin film or the two sides; Form the blocking layer through wet method; Form Seed Layer through wet method or dry method afterwards; And form conductive cell envelope through wet method on its top layer, it is characterized in that, on the release surface of this metal-coated polyimide resin substrate being carried out 90 ° of conductive cell envelope layer sides after the stripping test; Use time of flight secondary ion massspectrometry analytical equipment (TOF-SIMS) to carry out polyimide residue that the depth direction analysis obtains and the mixolimnion thickness of barrier metal layer residue is scaled below the 2.60nm with the Si sputtering rate, the stripping strength conservation rate (heat-resisting stripping strength/normality stripping strength) after 150 ℃, 168 hours weathering tests is more than 50%.The application invention is particularly under the situation of the initial stage closing force after not reducing Kapton and metal interlevel range upon range of, can improve the closing force after aging, therefore has excellent results aspect the formation fine pattern.The application invents as the good metal-coated polyimide resin substrate of non-adhesive flexible laminated material, particularly the stripping strength conservation rate of the installing material that is used as electronic units such as flexible printed board, TAB, COF useful.

Claims

1. metal-coated polyimide resin substrate; It is for after carrying out surface-treated through wet method or dry method or their combination on the single face of polyimide resin film or the two sides; Form the blocking layer through wet method, form Seed Layer through wet method or dry method afterwards, and form the metal-coated polyimide resin substrate that conductive cell envelope obtains through wet method on its top layer; It is characterized in that

2. metal-coated polyimide resin substrate as claimed in claim 1 is characterized in that,

Said Seed Layer and conductive cell envelope are copper, and said blocking layer is nickel or their alloy, and form through electroless plating method.

3. according to claim 1 or claim 2 metal-coated polyimide resin substrate is characterized in that,

Surface-treated on the said polyimide resin film is carried out through the combination of plasma body, UV, alkali hydroxide soln dip treating or they and strong acid solution dip treating.